Cucurbit aphid-borne yellows virus (CABYV, genus Polerovirus, family Luteoviridae) causing cucurbit aphid-borne yellows disease (CABYD) in groundnut ( Arachis hypogaea) is characterized by interveinal yellowing symptoms in leaves. CABYV is transmitted by Aphis gossypii, Myzus persicae, and Macrosiphum euphorbiae. CABYV causes up to 80% yield loss, but there is no information available on its occurrence and serological and molecular characteristics in groundnuts. Two disease diagnostic surveys were conducted during the short and long rains seasons of 2020 and 2021 in Bungoma, Busia, Kakamega, and Siaya counties growing groundnut. Disease incidence and severity were scored, and collected data were analyzed using R software. Serological bioassays were performed using TAS-ELISA, and positive samples were pooled and processed with the transposon-based chemistry library preparation kit (Nextera XT, Illumina). Phylogenetic analyses and comparisons were performed using the MEGA X software. In the short rains season higher incidence (73.61%) was recorded than in the long rains season (42.65%). The CABYV isolates from Kenya clustered with other poleroviruses variedly. CABYV6-2 showed 94.5% nucleotide identity with CpPV2 isolate KX599164.1 from Burkina Faso and 83.4% identity with CABYV isolate MG257902.1 from Korea. This research provides evidence for the first report of CABYV infecting A. hypogaea relevant for development of better plant health management technologies for increased groundnut yield.

The common bean (Phaseolus vulgaris L.) is a vital food crop worldwide, especially in Latin America, Asia, and Sub-Saharan Africa, due to its high levels of protein, fiber, and essential nutrients. However, it is vulnerable to viral infections, particularly from the Bean Common Mosaic Virus and Bean Common Mosaic Necrosis Virus. While previous research has largely focused on specific resistance genes, a broader understanding of the plant’s complete immune response remains limited. To investigate this, a study was conducted involving 51 infected leaf samples. RNA was extracted, and deep metatranscriptomic sequencing was performed using the Illumina MiSeq platform. The results indicated that several genes related to stress response, nitrogen metabolism, and biosynthesis pathways were activated during infection. Significant defense mechanisms included pathogen recognition, production of antimicrobial peptides, and alterations in metabolic activity. The Mitogen-Activated Protein Kinase (MAPK) signaling pathway and enzymes like glycosyl transferases, which help build protective structures, played a critical role. These findings suggest that the bean’s defense system is complex and involves not only direct attacks on pathogens but also metabolic shifts and microbial interactions. Understanding these processes provides valuable insights for breeding stronger, disease-resistant, and climate-resilient bean varieties.

Common bean production is crucial in Western Kenya due to its economic, nutritional, environmental, and cultural importance. However, challenges such as diseases, especially viral diseases, cause significant crop losses. This study sought to identify potential biomarkers for BCMV and BCMNV viral diseases by analyzing small molecule metabolites in diseased common bean systems and gain an understanding of related metabolic pathways. Virus-free Rosecoco bean cultivars were planted and exposed to BCMV and BCMNV in specific regions, with healthy plants serving as controls. Diseased and healthy leaves were collected for metabolite extraction and analyzed using liquid chromatography and mass spectrometry. A total of 354 metabolites were identified across seven pathways, with 51 upregulated metabolites, primarily from fatty acids, terpenoids, and alkaloids. Ten metabolites were differentially expressed, with the molecular structures of two successfully determined. These metabolites serve as potential biomarkers for viral disease detection, monitoring, and resistance in common beans. The findings highlight the role of fatty acids and terpenoids, as well as the importance of regional variability in plant hormone regulation in response to stress, suggesting that further research into these pathways will be essential for understanding plant defense mechanisms.

The metabarcoding of prokaryotic and fungal (Ascomycota only) ribosomal DNA was used to describe the microbial communities in soils of a remnant equatorial rainforest, maize–bean intercrop, and sugarcane in western Kenya. Cropping systems influenced the microbial community composition and functional traits (energy source and nutrient cycling) of bulk soil in each crop. Microbial richness and diversity tended to increase with cultivation intensity. The soil of the maize–bean intercrop had lower percentages and sugarcane had higher percentages of unique amplicon sequence variants of both bacteria and fungi compared to the remnant forest. Functional traits were altered by cultivation intensity. Compared to remnant forest soils, maize–bean intercrop soil had lower percentages of aerobic chemoheterotrophic bacteria and higher percentages of N-cycling bacteria, while sugarcane had higher percentages of aerobic chemoheterotrophic bacteria and lower percentages of N-cycling bacteria. In the face of increasing forest loss and pressures for agricultural productivity, this landscape provides a rich site for studying the impacts of cropping systems on soil health.

Brachiaria is a newly introduced forage grass in Kenya and other countries that has potential for improving livestock productivity but there is limited availability of seed this has become a major constraint. Pastures in western Kenya faces both pathological and physiological problems associated with both biotic and abiotic factors that leads to poor livestock production especially in the dairy industry. This research study focused on evaluating disease tolerance and growth potential of selected Brachiaria cultivars Xaraes (Xaraes palisade), Piata (Piatã palisade), MG4 in the selected agro-ecological zones of Western Region, Kenya. Mulato II grass was included as a control. The experiment was replicated three times at two different agro-ecological zones namely KALRO Kakamega LM2 and KALRO Alupe, Busia LM1 agro ecological zones therefore this study was a 2×3×5 factorial laid in a split plot. Root splits used as planting material were sourced from KALRO Kakamega farm. Phosphate fertilizer at the rate 40 kg/ha P2O5 were used at planting and the crop was top dressed with Nitrogen fertilizer at the rate 100 kg/ha N. Data collected included number of tillers, plant height at different stages, light interception, leaf area index and diseases incidence on the seeds. In LM1 Mulatto II had the highest height and Basilisks had the lowest height and vice versa for LM2. In both agro-ecological zones Basilisks had the highest number of tillers. In terms of disease establishment, in LM2 (KALRO-Kakamega); Basilisks was the most affected cultivar by both false smut and ergot diseases at 58% and 69.33% incidences respectively. MG4 had the least ergot incidence at 41%, while Xaraes had the least incidence for false smut at 32%. In LM 1 (Alupe Busia), no cultivar exhibited disease. Most cultivars intercepted light higher in LM2 and lower in LM1. Mulatto II and Xaraes had the highest and lowest light interception respectively in LM1 (Alupe Busia), while Basilisks and Xaraes had the highest and lowest interceptions respectively in LM2 (KALRO-Kakamega). The trends were the same in terms of LAI though MG4 had the lowest LAI in LM1. Through this study Basilisks, Xaraes, Mulatto II and Piata were moderately tolerant to ergot disease while MG4 was highly tolerant. Basilisks and MG4 were moderately tolerant to false smut disease while Xaraes had high tolerance levels This research serves as a baseline for future research on Brachiaria forage yield and provide knowledge-based information on production of high quality Brachiaria seeds with the view of enhancing their availability scaling-up Brachiaria forage production to enhance dairy productivity in smallholder farm.

The common bean (Phaseolus vulgaris L.) is a vital food crop worldwide, particularly in Latin America, Asia, and Sub-Saharan Africa, due to its high levels of protein, fiber, and essential nutrients. However, it is susceptible to viral infections, especially from the Bean common mosaic virus and Bean common mosaic necrosis virus. While previous research has primarily focused on specific resistance genes, a broader understanding of the plant’s overall immune response remains limited. To investigate this, a study was conducted involving 51 infected leaf samples. RNA was extracted, and deep metatranscriptomic sequencing was performed using the Illumina MiSeq platform. The results indicated that several genes related to stress response, nitrogen metabolism, and biosynthesis pathways were activated during infection. Key defense mechanisms included pathogen recognition, the production of antimicrobial peptides, and changes in metabolic activity. The Mitogen-Activated Protein Kinase (MAPK) signaling pathway and enzymes like glycosyl transferases, which aid in building protective structures, played a significant role. These findings suggest that the bean’s defense system is complex and involves not only direct attacks on pathogens but also metabolic shifts and microbial interactions. Understanding these processes provides valuable insights for breeding stronger, disease-resistant, and climate-resilient bean varieties.